Apparatus for chemical mechanical polishing

ABSTRACT

Embodiments of the invention generally relate to systems and methods to CMP substrates. The systems generally include a polishing system that has a polishing module and cleaning module. Each of the polishing module and the cleaning module can be partitioned into independently operable sections. Each section of the polishing module includes a platen, at least one load cup, and at least one polishing head. Each section of the cleaning module includes a cleaning station and one or more robots adapted to advance substrates through the cleaning station. The methods generally include polishing a plurality of substrates in a polishing system having independently operable sections. During the polishing of the substrates in one section, a second of the independently operable stations may be maintained or cleaned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to methods and apparatus for chemical mechanical polishing (CMP) of substrates.

2. Description of the Related Art

CMP is a known process used to planarize one or more surfaces of a substrate. Although many commercially available CMP systems have demonstrated robust polishing performance, the move to smaller line widths requiring more precise fabrication techniques, along with a continued need for increased throughput, drives an ongoing effort for polishing system improvements. Current commercially available systems polish substrates in a serial fashion through sequential stations on a polishing system. Down time due to maintenance or cleaning at one polishing station halts throughput of substrates on the entire polishing system, thus stopping production and increasing the cost to manufacture substrates.

Therefore, there is a need for a modular CMP system.

SUMMARY OF THE INVENTION

Embodiments of the invention generally relate to systems and methods to CMP substrates. The systems generally include a polishing system that has a polishing module and cleaning module. Each of the polishing module and the cleaning module can be partitioned into independently operable sections. Each section of the polishing module includes a platen, at least one load cup, and at least one polishing head. Each section of the cleaning module includes a cleaning station and one or more robots adapted to advance substrates through the cleaning station. The methods generally include polishing a plurality of substrates in a polishing system having independently operable sections. During the polishing of the substrates in one section, a second of the independently operable stations may be maintained or cleaned.

In one embodiment, an apparatus comprises a polishing module having a first polishing station and a second polishing station. A partition including a housing and an actuatable door is located within the polishing module between the first polishing station and the second polishing station. The actuatable door is adapted to be positioned to environmentally isolate the first polishing station from the second polishing station. An overhead track is disposed above the first polishing station and the second polishing station.

In another embodiment, an apparatus comprises a polishing module. The polishing module comprises a first polishing station, a second polishing station, and a partition. The partition includes a housing and an actuatable door located within the polishing module between the first polishing station and the second polishing station. The actuatable door is adapted to be positioned to environmentally isolate the first polishing station from the second polishing station. The polishing module also includes a curved overhead track disposed above the first polishing station and the second polishing station. The apparatus also comprises a cleaning module adjacent to and in operable communication with the polishing module. The cleaning module comprises a first cleaning station, a second cleaning station, and a central transfer region positioned between the first cleaning station and the second cleaning station. A trough is disposed at one end of the cleaning module in operable communication with the first cleaning station, the second cleaning station, and the central transfer region.

In another embodiment, a method of processing substrates in a polishing system having a polishing module and a cleaning module comprises partitioning at least one of the cleaning module and the polishing module into a first section and a second section. The method further comprises performing at least one of cleaning or maintenance on the first section while processing a plurality of substrates in the second section.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIGS. 1A and 1B are top plan views of a polishing system according to one embodiment of the invention.

FIG. 2 is a perspective view of a polishing station according to one embodiment of the invention.

FIGS. 3A and 3B are respective bottom and top isometric views of a polishing module lid.

FIG. 4 is an isometric view of a partition according to one embodiment of the invention.

FIG. 5 is a sectional view of a shuttle trough and shuttles according to one embodiment of the invention.

FIG. 6 is an isometric view of cleaning robots according to one embodiment of the invention.

DETAILED DESCRIPTION

Embodiments of the invention generally relate to systems and methods to CMP substrates. The systems generally include a polishing system that has a polishing module and cleaning module. Each of the polishing module and the cleaning module can be partitioned into independently operable sections. Each section of the polishing module includes a platen, at least one load cup, and at least one polishing head. Each section of the cleaning module includes a cleaning station and one or more robots adapted to advance substrates through the cleaning station. The methods generally include polishing a plurality of substrates in a polishing system having independently operable sections. During the polishing of the substrates in one section, a second of the independently operable stations may be maintained or cleaned.

FIGS. 1A and 1B are top plan views of a polishing system 100 according to one embodiment of the invention. The polishing system 100 includes a polishing module 101, a cleaning module 102, and a factory interface 103. The factory interface 103 includes a robot 104 disposed on a track 105. The robot 104 is adapted to remove a substrate 106 from one of the substrate storage cassettes 107 and transfer the substrate 106 to transfer platforms 180, through a port 110, such as a slit valve. The robot 104 is also configured to receive substrates from each cleaning station 109A, 109B through ports 111 subsequent to a cleaning process and return the cleaned substrates to the substrate storage cassettes 107. The ports 111 are shown as having an “L” shape; however, other shapes, such as linear, are contemplated. Although the robot 104 is shown as only supporting one substrate 106, it is contemplated that the robot 104 may simultaneously support more than one substrate 106.

The factory interface 103 is positioned adjacent to and in operable communication with the cleaning module 102. The cleaning module 102 includes two cleaning stations 109A, 109B, a central transfer area 112 located therebetween, and a shuttle trough 113 positioned at one end of the cleaning module 102 opposite the factory interface 103. The cleaning stations 109A, 109B are separated from the central transfer area by walls 117, which also extend over the upper surface of the shuttle trough 113. The cleaning stations 109A, 109B and the central transfer area 112 are in communication with one another only through the shuttle trough 113 during system operation. Each cleaning station 109A, 109B includes a plurality of cleaning units 115 and a dryer 120, each of which generally includes an opening formed in the upper portion thereof for accepting substrates therein. The cleaning units 115 may be one or more of brush boxes, rinsing stations, spray jet units, megasonic cleaners, or combinations of two or more thereof. Robots 116 are each connected to a track (not shown in FIG. 1A) disposed in each of the cleaning stations 109A, 109B and coupled to a surface of the walls 117. The robots 116 are adapted to move a substrate received from the shuttle trough 113 through each of the cleaning units 115 to the dryer 120. The dryer 120 has an output station (not shown) through which the substrate is presented for transfer to the robot 104, which then stores the substrate in the substrate storage cassettes 107. For example, a first robot 116 may be adapted to move substrates through a first set of cleaning units 115, such as the first two cleaning units 115, while a second robot 116 may be adapted to move the substrate through a second set of cleaning units 115 and the dryer 120.

The central transfer area 112 of the cleaning module 102 is in communication with the factory interface 103 and the polishing module 101 through ports 110 and 118, respectively, each of which may be selectively and independently opened and closed. The central transfer area 112 includes two transfer platforms 180, two buffer stations 108A, 108B and a robot 119 adapted to transfer two substrates simultaneously from the transfer platforms 180 to the interior of the polishing module 101 through one of the ports 118. One or more substrates may optionally be vertically positioned in the buffer stations 108A, 108B, which contain a solution such as deionized water, to maximize throughput. In such an embodiment, the robot 119 may remove substrates from the buffer stations 108A, 108B. The robot 119 includes a linkage assembly 124 coupled to an overhead track or linkage (not shown), a robot body 127 coupled to the linkage assembly 124, and two end effectors 126 coupled to the robot body 127. The robot 119 is adapted to remove substrates from the transfer platforms 180 and transfer the substrates into the polishing module 101 to load cups 121A and 121B, or 122A and 122B through a respective port 118. The robot 119 is also adapted to remove substrates from the load cups 121A and 121B, or 122A and 122B after a polishing process, and dispose the substrates in the shuttle trough 113 through openings 125 located in the upper surface of the shuttle trough 113. The end effectors 126 each generally include at least one gripping device, such as a mechanical clamp or suction device in order to secure substrates thereto.

The shuttle trough 113 accepts substrates in a vertical orientation for placement on a shuttle located therein, as will be explained in further detail with reference to FIG. 5, and transfer the substrates to a location proximate the cleaning stations 109A, 109B (i.e., adjacent to openings 137) to facilitate transfer to the robots 116. The robot 119 is adapted to pivot at the connection between the robot body 127 and the linkage assembly 124 to allow the end effectors 126 to assume a vertical orientation for transfer of polished substrates through the openings 125 located in the shuttle trough 113.

The polishing module 101 includes a plurality of polishing stations 128 on which substrates are polished on polishing pads 135 while retained in polishing heads 131A, 131B, 132A, and 132B. The polishing stations 128 are sized to interface with at least one polishing head so that at least one substrate may be polished in the polishing station 128. In the embodiment depicted in FIGS. 1A-1B, the polishing stations are sized to interface with at least two polishing heads simultaneously so that polishing of multiple substrates at the same polishing station 128 may occur at the same time. Each polishing station 128 includes one or more pad conditioners 134 for conditioning an upper surface of the polishing pad 135, and one or more fluid delivery arms 136 for delivering a polishing fluid, such as a polishing slurry or rinse fluid, to the upper surface of the polishing pad 135. In the embodiment depicted in FIGS. 1A-1B, each polishing station 128 includes at least two pad conditioners 134 and at least 2 fluid delivery arms 136.

The polishing heads 131A, 131B, 132A, and 132B are coupled to carriages that are mounted to an overhead track 130 (shown in phantom). The overhead track 130 allows the polishing heads 131A, 131B, 132A, and 132B to be selectively positioned around the polishing module 101 including over the polishing pads 135 disposed in the polishing stations 128 and load cups 121A, 121B, 122A, and 122B. Thus, the polishing heads 131A, 131B, 132A, and 132B are movable along the track 130 to a position over the load cups 121A, 121B, 122A, and 122B where substrates can be engaged and retained by the polishing heads 131A, 131B, 132A, and 132B. The polishing heads 131A, 131B, 132A, and 132B can then return to a position over a selected one of the polishing stations 128 via movement along the track 130 for polishing of the substrates on the polishing pads 135. The track 130 shown in FIG. 1A has a curved shape. Ends 190A and 190B of the track 130 define an opening 191 on a side of the polishing module 101 opposite the cleaning module 102. The opening 191 of the track 130 provides a space to accommodate the partition 129 which extends inwardly from one wall of the polishing module 101. It is contemplated that the track 130 may have other shapes, including linear, elliptical, circular or other shape. It is further contemplated that the track 130 may not have the opening 191, and thus, have a completely circular shape, as long as the track 130 can still accommodate the partition 129.

The above description describes the structure of the polishing system 100; and now the movement of substrates through the polishing system 100 will be described. The robot 104 unloads substrates 106 from the substrate storage cassettes 107 and transfers the substrates to the transfer platforms 180 through the port 110. The robot 119 then engages and lifts one substrate from each of the transfer platforms 180 simultaneously. The robot rotates approximately 180 degrees and enters the polishing module 101 to position the substrates on the load cups 121A, 1216 through the respective port 118 closest to load cups 121A, 121B. The robot 119 is then retracted from the polishing module 101.

The polishing heads 131A, 131B travel along the track 130 to a position above the load cups 121A, 121B. The polishing heads 131A, 131B actuate downward to engage and secure a substrate from one of the load cups 121A, 121B, respectively. The polishing heads 131A, 131B then lift upward to provide sufficient clearance of the load cups 122A, 122B and return to a position above the polishing station 128. During the movement of the polishing heads 131A, 131B, the robot 119 disposes two additional substrates from the transfer platforms 180 on to the load cups 122A, 122B, respectively, through the respective port 118. After the polishing heads 131A, 131B are clear of the load cups 121A, 121B, the polishing heads 132A, 132B move along the track 130 to a position above the load cups 122A, 122B, and secure substrates from the load cups 122A, 122B. The polishing heads 132A, 132B then return to the other polishing station 128 to polish the substrates.

While polishing heads 132A, 132B are engaging substrates from load cups 122A, 122B, the robot 119 is reloading load cups 121A, 121B. Simultaneously, after completion of the polishing of the substrates located in polishing heads 131A, 131B, the polishing heads 131A, 131B rotate along the track to a position over the unoccupied load cups 122A, 122B, respectively, and dispose the polished substrates in the load cups 122A, 1226. The polishing heads 131A, 131B then continue along the track to the load cups 121A, 121B to engage two new substrates, and the polishing process is repeated. While the polishing heads 131A, 131B return to the polishing station 128, the robot 119 removes the polished substrates from the load cups 122A, 122B and disposes the polished substrates in the openings 125 of the shuttle trough 113. Each of the polished substrates is disposed on a shuttle (shown in FIG. 5) located within the shuttle trough 113, and transferred via a shuttle to one of the cleaning stations 109A, 109B. The shuttles are independently operable to allow a first shuttle to carry a first substrate to the cleaning station 109A, and to allow a second shuttle to carry a second substrate in an opposite direction to cleaning station 109B.

The polished substrates are then removed from the shuttle trough 113 through openings 137 by respective robots 116 located in each of the cleaning stations 109A, 109B. A first robot 116 in each of the cleaning stations 109A, 109B advance the polished substrate through a first set of the cleaning units 115, such as the first two cleaning units 115. A second robot 116 in each of the cleaning stations 109A, 109B removes the substrate from the last cleaning unit 115 of the first set of cleaning units 115, and then advances the substrate through the remainder of the cleaning units 115 and the dryer 120. The cleaned substrates are then removed from the cleaning stations 109A, 109B by the robot 104 and stored in the substrate storage cassettes 107.

FIG. 1B is a top plan view of the polishing system 100 having the partition 129 positioned to separate and form a seal, for example an air tight seal, between sections of the polishing module 101. The partition 129 includes a housing 140 and an actuatable door 141 which extends from the housing 140 to form a substantially environmentally-isolating seal (in conjunction with the closed ports 118) across the polishing module 101 to separate the polishing stations 128 from one another. Thus, the polishing module,101 is divided into two independently operable sections 101A and 101B, wherein each section includes at least one load cup and one polishing station. The partition 129 separates the sections 101A and 1018 from one another thus providing isolation therebetween. In such a configuration, one of the sections 101A or 101B can be shut down for maintenance or cleaning, while the other section 101A or 1018 can continue to operate uninterrupted and unaffected by the shut down section. Therefore, throughput of the polishing system 100 is reduced only by about 50 percent, instead of completely shutting down, when maintenance or cleaning within the polishing module is necessary. The partition 129 allows each section 101A or 101B to be safely maintained by providing a barrier between each of the sections 101A, 1018. Additionally, the partition 129 forms an environmentally-isolating seal across the polishing module 101 isolating section 101A from section 101B, which reduces the probability of particulate contamination between the adjacent section 101A or 101B due to cleaning or maintenance of the other section 101A or 101B. Furthermore, the environmentally-isolating seal formed by the partition 129 reduces variations in air flow within the section 101A or 1018 during a polishing process, which ensures uniform polishing from substrate to substrate.

When one of the sections 101A, 101 B is shut down for maintenance or cleaning, substrate movement through the system is slightly different with the partition 129 closed than when the entire polishing system 100 is operational. Specifically, the polishing heads 131A and 131B, or 132A and 1326 use only the load cups positioned adjacent thereto in the same section 101A or 101B as the respective polishing heads. The polishing heads 131A, 131B, 132A, 132B are unable to access the load cups on the opposite side of the polishing module 101 due to extension of the actuatable door 141. Furthermore, the port 118 on the respective side of the section 101A, 101B generally remains closed during the maintenance or cleaning of section 101A, 101B to maintain environmental isolation.

Not only can the polishing module 101 be partitioned into independently operable sections, but the cleaning module 102 can also be partitioned into independently operable sections. For example, either of the cleaning stations 109A and 109B can be shut down for cleaning or maintenance, while the other cleaning station 109A or 109B continues to process substrates. As discussed above, the cleaning stations 109A, 109B and the central transfer area 112 are separated by walls 117, and are in operable communication only through the shuttle trough 113. Thus, partitioning of the shuttle trough 113 adjacent to the walls 117 isolates a respective cleaning station 109A or 109B from the remainder of the cleaning module 102, allowing for cleaning or maintenance of the respective partitioned cleaning station 109A or 109B. The shuttle trough 113 can be partitioned via actuatable trough partitions 138, which are shown in phantom in FIG. 1B and further described with reference to FIG. 5.

When the cleaning module 102 is partitioned for cleaning or maintenance of one of the cleaning stations 109A, 109B, the transfer of substrates from the polishing module to the operable cleaning station is different than when the entire cleaning module 102 is operable. When one of the cleaning stations 109A or 109B is shutdown, for example cleaning station 109B, the robot 119 removes one polished substrate at a time from either of the first set of load cups 121A or 121B, or the second set of load cups 122A and 122B. For example, if polished substrates are located on load cups 122A and 122B, the robot removes a polished substrate from the load cup 122A, retracts the polished substrate into the cleaning module 102 while rotating 180 degrees, and places the substrate in the shuttle trough through opening 125 closest to the cleaning station 109A. A shuttle 570 (shown in FIG. 5) then transports the substrate through the shuttle trough 113 to a location adjacent to opening 137, where the substrate is picked up by a first robot 116 and transported through the cleaning station 109A. The shuttle 570 then returns to a position beneath the other opening 125 farthest from the cleaning station 109A. The robot 119 then removes a polished substrate from the other load cup 122B, and positions the substrate on the shuttle 570 through the other opening 125. The shuttle then transports the substrate to the opening 137 proximate to the cleaning station 109A, where the substrate is picked up by a robot 116 and transported through the cleaning station 109A. Thus, when one of the cleaning stations 109A or 109B is partitioned off for cleaning or maintenance, substrates are transferred to the operable cleaning station one at a time. Transferring the substrates one at a time using a single shuttle 570 allows a second shuttle 570 to be maintained simultaneously with one of the cleaning stations 109A or 109B.

It is to be noted that the polishing module 101, the cleaning module 102, or both may be simultaneously partitioned. In an embodiment where both the polishing module 101 and the cleaning module 102 are partitioned, it is not necessary to shut down a cleaning station 109A or 109B and a polishing section 101A or 101B on the same side of the polishing system 100. For example, the polishing module 101 may be partitioned for cleaning of section 101A, while the cleaning module 102 is partitioned for cleaning of the cleaning station 109B. The ability to partition either or both of the polishing module 101 and the cleaning module 102 assists in cleaning, maintenance, engineering evaluation, or particle apportionment in the polishing system 100.

FIGS. 1A and 1B illustrate one embodiment of a polishing system 100; however, additional embodiments are also contemplated. For example, it is contemplated that the polishing module 101 may include more than two polishing stations 128, such as three polishing stations 128 or four polishing stations 128. It is also contemplated that polishing pads 135 on the polishing stations 128 may be a polyurethane pad or a fixed abrasive pad. It is further contemplated that polishing stations 128 may be adapted to polish 200 millimeter, 300 millimeter, and/or 450 millimeter substrates, or that the polishing stations 128 may be adapted to polish a single substrate at a time. It is also contemplated that the polishing module 101 may be utilized in conjunction with cleaning modules other than the cleaning module 102.

Additionally, it is contemplated that the independently operable sections 101A and 101B need not contain identical polishing components. For example, it is contemplated that one of the independently operable sections 101A or 101B could contain a platen with load cups, as illustrated, while the other independently operable section contains bevel polishing components or other course polishing/grinding stations. Furthermore, it is contemplated that the actuatable door 141 may be positioned to actuate vertically, rather than horizontally from the housing 140.

FIG. 2 is a perspective view of a polishing station 128 according to one embodiment of the invention. The polishing station 128 includes a platen 242 having a shaft 243 coupled to a motor 244 which is adapted to rotate the shaft 243 and the platen 242 coupled thereto. The polishing pad 135 is disposed on the upper surface of the platen 242 and acts as a polishing surface during a chemical mechanical polishing process. A substrate is retained against the upper surface of the polishing pad 135 during polishing by each polishing head 132A, 132B. The polishing heads 132A, 132B are coupled to carriages 245 by rotatable and vertically actuatable shafts 246. The carriages 245 are coupled to the track 130 supported above the platen 242 and below a polishing module lid 247. The carriages 245 can be selectively positioned along the track 130 within the polishing module. The carriages 245 are moved along the track 130 using an actuator (not shown), such as a magnetic actuator, a gear motor, a servo motor, a linear motor or other motion control device suitable for positioning the carriages 245 along the track 130. The carriages 245 are used to position the polishing heads 132A, 132B over the load cups, to sweep the polishing heads 132A, 132B over the polishing pad 135, or to position the polishing heads 132A, 132B clear of the load cups or polishing pad 135 for maintenance.

Rotatable fluid delivery arms 136 are positioned on opposite sides of the platen 242 and are adapted to apply one or more fluids to the upper surface of the polishing pad 135. For example, the fluid delivery arms 136 may apply one or more of a polishing slurry, a rinsing solution, or a conditioning solution to the upper surface of the polishing pad 135. Rotatable pad conditioners 134 are positioned adjacent to each of the fluid delivery arms 136. The pad conditioners 134 are adapted to contact and sweep across the polishing pad 135 to condition the upper surface thereof.

FIGS. 3A and 3B are respective bottom and top isometric views of a polishing module lid 247. The polishing module lid 247 is adapted to be positioned over the polishing module 101 (shown in FIG. 1A) and supports a track 130 on the bottom surface thereof. The track 130 includes an outer edge 350, an inner edge 351, and a stator 352 disposed therebetween. The outer edge 350 and the inner edge 351 define the curved track 130. The track has ends 190A and 190B which define an opening 191 in one portion of the track 130. The opening 191 is positioned to accommodate the housing 140 of the partition 129 (shown in FIG. 1B). An encoder scale 354 is coupled to the polishing module lid 247 and is adapted to detect the position of carriages 245.

The track 130 is shown has having four carriages 245 coupled thereto; however, it is contemplated that more or less than four carriages 245 may be coupled to the track 130. The carriages 245 are independently movable along the track 130 to selectively position the carriages 245 and the polishing heads coupled thereto about the track 130. For example, each carriage 245 may include a coil that interfaces with the stator 352 of the track 130. In such an example, the stator 352 includes magnets arranged in alternating polarity so that each carriage 245 may be moved independently of the other carriages 245 coupled to the track 130 by controlling the magnetic field generated by the coil.

A movable seal 356 is also coupled to the track 130. The movable seal 356 includes a slit 357 therein which is adapted to be engaged by the actuatable door 141 of the partition 129 (shown in FIG. 1B) to form a wall across the polishing module. The slit 357 may include a rubber seal or lining therein to increase the sealing ability of the movable seal 356. When the movable seal is engaged by the actuatable door 141, pins 358 may be disposed through the polishing module lid 247 to engage and secure the movable seal 356 in place. The pins 358 are shown in the top isometric view of the polishing module lid 247 shown in FIG. 3B. The pins 358 may engage the movable seal 356, for example, via pneumatic actuation.

Returning to FIG. 3A, when the actuatable door 141 is not engaged with the movable seal 356, for example, during normal operation of the polishing module 101, the movable seal 356 travels along the track 130. Movement of the movable seal 356 along the track 130 allows the carriages 245 to be positioned over both sets of load cups in the polishing module. Since the range of motion of each carriage 245 is at least approximately 135 degrees (from one polishing station to an oppositely positioned set of load cups), the movable seal 356 travels along the track in the same direction of movement as each set of carriages 245 to accommodate the movement of the carriages 245. Thus, during polishing, the movable seal 356 continuously shifts in a clockwise and then counter-clockwise direction synchronized with the movement of the carriages 245. In order to effect movement of the movable seal 356, the movable seal 356 may include a linear motor similar to the carriages 245. The movable seal 356 may additionally include one or more metrology devices integrated therewith for monitoring conditions within the polishing module. For example, the movable seal 356 may include a pad metrology unit, a substrate defect mapping device, a camera or video device, or a laser.

FIG. 4 is an isometric view of the partition 129 according to one embodiment of the invention. The partition 129 includes a housing 140 having an opening 460 which receives the actuatable door 141. The actuatable door 141 is actuated along a track 461 via an actuator 465, such as a motor, and engages a seal 462 located on the wall 463. The wall 463 separates the polishing module 101 from the cleaning module 102 (as shown in FIG. 1A) and includes ports 118 therethrough. The upper edge 464 of the of the actuatable door 141 is adapted to engage the slit 357 in the movable seal 356 (as shown in FIG. 3A) to form a seal when partitioning the cleaning module into independently operable sections. The upper surface 466 of the housing 140 is in contact with the lower surface of the polishing module lid 247. The upper surface 466 has an opening 468 therein adapted to engage the encoder scale 354 (shown in FIG. 3A). The partition 129 is generally formed from a polymer or a metal material, such as stainless steel, or another material which does not introduce undesired contamination into the polishing module.

FIG. 5 is a sectional view of the shuttle trough 113 and shuttles 570 according to one embodiment of the invention. The shuttles 570 are used to move substrates 106 returning from the polishing module (entering the shuttle trough 113 through openings 125) to a load position beneath openings 137 where the substrates 106 can be picked up by a cleaning station robot and moved through a respective cleaning station. Although two shuttles 570 are shown, it is contemplated that more or less shuttles may be utilized. The shuttle trough 113 includes a trough body 571 adapted to hold a fluid 572, such as a rinsing solution, therein. A track 576 is disposed within the trough body 571 to which the shuttles 570 are coupled to facilitate transfer of the substrates 106 within the shuttle trough 113. Alternatively, it is contemplated that the track may be disposed outside the shuttle trough 113, and connected to the shuttles 570 via a slit through the back surface of the shuttle trough 113. The shuttles 570 include substrate support 577, such as a clamp, gripper, or grooved wafer holder, a track mount 578, and a stem 579 coupled therebetween. Each track mount 578 generally includes an actuator to facilitate movement of the shuttles 570 along the track 576 and to provide independent actuation to each of the shuttles 570.

The trough body 571 includes a roof portion 573 through which openings 125 and 137 are disposed. The partitions 138 are pivotally connected to the lower surface of the roof portion 573 by hinges 574. The hinges 574 are adapted to pneumatically or mechanically actuate the partitions 138. The partitions 138 are adapted to pivot into a vertical position, as shown in phantom, to isolate one portion of the shuttle trough 113 from the remainder of the shuttle trough 113. One of the partitions 138 is generally actuated on a respective side of the shuttle trough 113 adjacent to a cleaning station during cleaning or maintenance of the cleaning station. The vertically-positioned partition 138 isolates the shutdown cleaning station from the remainder of the cleaning module. One of the shuttles 570 may be located behind the partition 138 adjacent to the partitioned cleaning station to allow access to the shuttle 570 for cleaning or maintenance at the same time as cleaning or maintenance of the shutdown cleaning station. Drains 580 are disposed through the lower surface of the trough body 571 near the outer edges of the shuttle trough 113 for draining the fluid 572 in the partitioned section of the shuttle trough 113 to facilitate access to the shuttle 570 located therein.

FIG. 6 is an isometric view of cleaning robots 116 according to one embodiment of the invention. The cleaning robots 116 are adapted to remove polished substrates from the shuttle trough 113 through opening 137 (shown in FIG. 5) and transfer substrates through a cleaning station. The robots 116 are disposed on a track 682 and are adapted to be positioned above a cleaning station. The robots 116 are coupled to the track 682 by mounts 683. The mounts 683 include motors for independently moving the robots 116 along the track 682. The mounts 683 additionally include actuators to effect vertical movement of the robot 116 relative to the track 682. The vertical movement of the robots 116 facilitates movement of substrates into and out of the cleaning units 115 and the dryers 120 (shown in FIG. 1A).

The robots 116 further include horizontal arms 684 for positioning clamps 685 above the cleaning units 115 and the dryers 120. The clamps 685 are adapted contact the edges of substrate 106 to hold the substrate 106 therein as shown in phantom. The clamps 685 are coupled to the horizontal arms 684 by movable bases 686 which are actuatable along the horizontal arms 684. Actuation of the clamps 685 allows for increased alignment precision of the clamps 685 with the openings within the cleaning units 115 and the dryers 120.

Benefits of the present invention include a modular polishing system which can be partitioned into independently operable sections. Some of the partitioned independently operable sections can then be maintained while the remainder of the sections simultaneously process substrates. Thus, system throughput is not halted due to maintenance at one location on the system. Additionally, throughput of the system is higher when all stations of the system are operational, especially compared to two independent polishing modules having the same total amount of platens, due to modular polishing system's ability to share modules while the system is in full production mode. Furthermore, the footprint of the modular polishing system is smaller than two separate polishing systems.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. 

1. An apparatus, comprising: a polishing module having a first polishing station and a second polishing station; a partition including a housing and an actuatable door located within the polishing module between the first polishing station and the second polishing station, the actuatable door adapted to be positioned to environmentally isolate the first polishing station from the second polishing station; and an overhead track disposed above the first polishing station and the second polishing station.
 2. The apparatus of claim 1, wherein the at least two polishing stations are independently operable when separated by the partition.
 3. The apparatus of claim 1, wherein the overhead track includes a movable seal coupled thereto, the movable seal adapted to be engaged by the actuatable door.
 4. The apparatus of claim 1, wherein the actuatable door is adapted to be positioned within the housing and extend therefrom.
 5. The apparatus of claim 4, wherein the actuatable door is positioned on a track.
 6. The apparatus of claim 5, wherein the actuatable door, when extended from the housing, forms a substantially air-tight seal separating the first polishing station from the second polishing station.
 7. The apparatus of claim 1, further comprising a cleaning module coupled to the polishing module, the cleaning module having a first cleaning station, and second cleaning station, and a central transfer area disposed therebetween.
 8. The apparatus of claim 7, further comprising a trough having at least two shuttles therein, the trough in operable communication with the first cleaning station, the second cleaning station, and the central transfer area.
 9. The apparatus of claim 8, wherein the trough further comprises a plurality of partitions actuatable to selectively partition portions of the trough.
 10. The apparatus of claim 9, wherein actuation of at least one the plurality of trough partitions isolates the first cleaning station from the central transfer region and the second cleaning station.
 11. An apparatus, comprising: a polishing module, the polishing module comprising: a first polishing station; a second polishing station a partition including a housing and an actuatable door located within the polishing module between the first polishing station and the second polishing station, the actuatable door adapted to be positioned to environmentally isolate the first polishing station from the second polishing station; and a curved overhead track disposed above the first polishing station and the second polishing station; a cleaning module adjacent to and in operable communication with the polishing module, the cleaning module comprising: a first cleaning station; a second cleaning station; a central transfer region positioned between the first cleaning station and the second cleaning station; and a trough disposed at one end of the cleaning module, the trough in operable communication with the first cleaning station, the second cleaning station, and the central transfer region.
 12. The apparatus of claim 11, wherein the actuatable door is adapted to be positioned within and extend from the housing.
 13. The apparatus of claim 14, further comprising a movable seal coupled to the curved track, wherein the movable seal includes a slot adapted to be engaged by the actuatable door of the partition.
 14. The apparatus of claim 12, wherein the trough comprises a plurality of actuatable partitions therein.
 15. A method of processing substrates in a polishing system having a polishing module and a cleaning module, comprising: partitioning at least one of the cleaning module and the polishing module into a first section and a second section; and performing at least one of cleaning or maintenance on the first section while processing a plurality of substrates in the second section.
 16. The method of claim 15, wherein partitioning at least one of the cleaning module and the polishing module comprises partitioning the polishing module, and wherein performing at least one of cleaning or maintenance comprises cleaning or maintaining the first section of the polishing module while processing a plurality of substrates in the second section of the polishing module and in the cleaning module.
 17. The method of claim 16, wherein partitioning the polishing module comprises actuating a door across the polishing module to separate a first polishing station from a second polishing station.
 18. The method of claim 15, wherein partitioning at least one of the cleaning module and the polishing module comprises partitioning the cleaning module, and wherein performing at least one of cleaning or maintenance comprises cleaning or maintaining the first section of the cleaning module while processing a plurality of substrates in the second section of the cleaning module and in the polishing module.
 19. The method of claim 18, wherein partitioning the cleaning module comprises actuating a partition located within a trough of the cleaning module.
 20. The method of claim 15, wherein partitioning at least one of the cleaning module and the polishing module comprises partitioning both the cleaning module and the polishing module. 